...he does seem to again want to underline that the philosophical muddle appears able to be “solved” (resolved) by an investigation that finds something new, rather than a philosophy which asks “‘What do we call 'getting to know' or, 'finding out'?’” to “break the spell of those [notations] which we are accustomed to.” — Antony Nickles

To understand this examine the following example: It might be found practical to call a certain state of decay in a tooth, not accompanied by what we commonly call toothache, "unconscious toothache" and to use in such a case the expression that we have toothache, but don't know it. It is in just this sense that psychoanalysis talks of unconscious thoughts, acts of volition, etc. Now is it wrong in this sense to say that I have toothache but don't know it? There is nothing wrong about it, as it is just a new terminology and can at any time be retranslated into ordinary language. On the other hand it obviously makes use of the word "to know" in a new way. If you wish to examine how this expression is used it is helpful to ask yourself "what in this case is the process of getting to know like?" "What do we call 'getting to know' or, 'finding out'?"

It’s fine, but you and Joshs maybe should take a look at pages 14-15 as it is a discussion of reasons (vs causes), and it also may help straighten out a few things. First, nowhere is he discussing what is the correct or incorrect use of language, nor any explanation of what gives it any normative force. Also, he is not denying that we each have our sense data (aka feelings), only that they are not “objects”, subject to fixed knowledge (or ‘ownership’). Thus, they are not the “cause” of our language use, but we give reasons for their expression (after the fact), as @Ludwig V points out. We are thus responsible for our acts and speech, not whether they are “correct” or not. — Antony Nickles

And what does Wittgenstein tell us about the authority of norms, customs and rules of language when it comes to the actual correct USE of language? As Joseph Rouse interests Wittgenstein:

…we cannot appeal to social regularities or collectively presupposed norms within a practice: there are no such things, I have argued, but more important, if there were they would not thereby legitimately bind us. Any regularities in what practitioners have previously done does not thereby have any authority to bind subsequent performances to the same regularities. The familiar Wittgensteinian paradoxes about rule following similarly block any institution of norms merely by invocation of a rule, since no rule can specify its correct application to future instances (Wittgenstein 1953). Practices should instead be understood as comprising performances that are mutually interactive in partially shared circumstances. — Joshs

197. [...] Where is the connection effected between the sense of the words
“Let’s play a game of chess” and all the rules of the game? — Well, in
the list of rules of the game, in the teaching of it, in the everyday practice
of playing.

198. [...] “So is whatever I do compatible with the rule?” — Let me ask this:
what has the expression of a rule — say a signpost — got to do with
my actions? What sort of connection obtains here? — Well, this one,
for example: I have been trained to react in a particular way to this
sign, and now I do so react to it.
But with this you have pointed out only a causal connection; only
explained how it has come about that we now go by the signpost; not
what this following-the-sign really consists in. Not so; I have further
indicated that a person goes by a signpost only in so far as there is an
established usage, a custom.

199. [...] To follow a rule, to make a report, to give an order, to play a game of
chess, are customs (usages, institutions).
To understand a sentence means to understand a language. To understand
a language means to have mastered a technique.

201. [...] there is a way of grasping a rule which is not an interpretation, but which,
from case to case of application, is exhibited in what we call “following the rule” and
“going against it”.

202. That’s why ‘following a rule’ is a practice. And to think one is
following a rule is not to follow a rule. And that’s why it’s not possible to
follow a rule ‘privately’; otherwise, thinking one was following a rule
would be the same thing as following it. — Wittgenstein, Philosophical Investigations

I think W leaves a gaping hole in the demonstration that mental objects - in the "occult" sense, drop out of consideration as irrelevant. But what makes the reasons mine, as opposed to justifications after the event? Perhaps the fact that I give them as reasons after the event is what makes them mine. In giving them, I claim them, or perhaps acknowledge them. Either way, they are to be compared to "I am in pain" or "That tastes sweet". There is a complicated hinterland here, which is usually acknowledged only in passing, that one's authority in such cases is defeasible. We may be joking or pretending. But it's time to move on. — Ludwig V

Your visible/invisible distinction seems irrelevant, at least for the one imagining the cat.
— Luke

A cartoonist who imagines a fictional cat might find it relevant to also see visible cats. — jkop

However, there's a feeling in what it's like to see the cat, which is comparable with a feeling of what it's like to see the cat-picture. There's also a feeling in what it's like to imagine a cat. You can compare your feelings (via memories), and judge resemblances between them. — jkop

No, I just feel them. What I feel is my physiological state, in which hormones and neurotransmitters etc are constitutive for having it. — jkop

But feelings are invisible, you can't compare a visible cat nor graphic image with the feeling of imagining what they look like. You can, however, compare things of the same type, such as two visible cats, two visible images, or two invisible mental states by how they feel when you have them. — jkop

A "mental image" couldn't even resemble visible objects such as cats or images — jkop

Well, for example, alcohol can affect my mental state so that I feel tipsy, a blurry kind of feeling, which in turn resembles the blurry feeling of seeing blurry or expressive pictures, or hearing blurry sounds, etc. There is something genuinely blurry about feeling tipsy, or in what it's like to see blurry pictures etc. — jkop

Imagining a cat may resemble seeing a cat (or cat-like doodle) since the levels of hormones and neurotransmitters that evoke the mental states in both cases can be similar or the same. Hence their resemblance. — jkop

A "mental image" couldn't even resemble visible objects such as cats or images — jkop

What's mental is the intent to find out what the cat might look like, which may feel like seeing, since it can be satisfied by one's ability to use memories and beliefs about cats. It can also be satisfied by doodling with a pencil on paper until the visible shapes of a drawn cat satisfy what you had in mind. But what you had in mind was never an image, only a hunch, a feeling evoked by the intent etc. — jkop

We can understand the meaning of a word, say the German word for "village" and have not the first clue how to use it in a sentence. — Count Timothy von Icarus

Yet we can also know how to use words without knowing what they mean. For example, plenty of people use "e.g." "QED," "i.e.," or "amen," correctly without knowing what they mean. — Count Timothy von Icarus

Is there a difference between knowing someone's pain and knowing that someone is in pain? — Michael

We cannot know other minds because our relation to others is not knowledge, but how we treat them, our “attitude” in relation to them, in its sense of: position “towards”. I treat you as if you have a soul. — Antony Nickles

As with others’ souls (p. 178) or the pain causing another to writhe in front of us (p. 235), we do not know it, because that is not how knowledge works. We respond to them (or ignore them). That is how humanity and pain are treated, the way in which they matter to us, their grammar. — Antony Nickles

There are two different senses of “know” here at p. (246), one being: with certainty, the other being knowing as acknowledging, recognizing. The part of the sentence you are quoting is the second kind. “I’m in pain.” “I know” or “He’s in pain!” “I know, but he’s so dramatic, he’ll be fine.” — Antony Nickles

Another’s pain is not known, it is responded to — Antony Nickles

I walked into that. But at the start of the sentence he says “If we are using the word ‘to know’ as it is normally used…” — Antony Nickles

As with others’ souls (p. 178) or the pain causing another to writhe in front of us (p. 235), we do not know it, because that is not how knowledge works. We respond to them (or ignore them). — Antony Nickles

Yes, hence the epistemological problem of perception. — Michael

Naive realists claim that sensory perception does provide us with direct knowledge of distal objects because distal objects are literal constituents of conscious experience, and so we are acquainted with distal objects.

Indirect realists claim that sensory perception does not provide us with direct knowledge of distal objects because distal objects are not literal constituents of conscious experience, and so we are only acquainted with mental phenomena. — Michael

It's only equivocation if they start from the premise that we are acquainted with mental phenomena and then conclude that our eyes respond to light reflected by mental phenomena, but they never draw this conclusion. This is the strawman conclusion that you and others are fabricating. — Michael

What indirect realists mean by "perception of some other entity" isn't what you mean by "perception of some other entity". You're equivocating. — Michael

Except by this you mean "our eyes respond to light reflected by sense data" which isn't what indirect realists believe. — Michael

So what is it that indirect realists believe that you do not? — Michael

As I've stated several times now, it is over part (2) of Fish's definition:
— Luke

Except according to what you mean by "perceive some other entity, such as sense-data", (2) is something that indirect realists accept. — Michael

You think that by "we perceive mental phenomena" the indirect realist means "our eyes respond to light reflected by mental phenomena". They don't. — Michael

where is it that non-naive direct realism and indirect realism disagree? — Michael

(2) that our visual perception of [...] material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part);

Naive realists claim that distal objects and their properties are literal constituents of conscious experience and that as such we are acquainted with distal objects and their properties, and so our knowledge of them is direct and there is no epistemological problem of perception. The external world just is as it appears. They call this "direct perception of distal objects". — Michael

Naïve realism is a theory in the philosophy of perception: primarily, the philosophy of vision. Historically, the term was used to name a variant of “direct realism,” which claimed (1) that everyday material objects, such as caterpillars and cadillacs, have mind-independent existence (the “realism” part); (2) that our visual perception of these material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part); and (3) these objects possess all the features that we perceive them to have (the “naïve” part).

Indirect realists don't believe or claim that our eyes respond to light reflected by mental phenomena and that our ears respond to sound emitted by mental phenomena, so you clearly misunderstand indirect realism and are arguing against a strawman. — Michael

What do you think "perceive mental phenomena" means? Do you think it means that my eyes respond to light reflected by mental phenomena? Do you think it means that my ears respond to sound emitted by mental phenomena? — Michael

I think you're reading something into the meaning of "perceive mental phenomena" that just isn't there. Indirect realists probably aren't saying what you think they're saying when they say that we perceive mental phenomena. Acquaintance with mental phenomena is the appropriate interpretation. — Michael

This is how to interpret the meaning of "feel" in "I feel pain" and the meaning of "hear" in "the schizophrenic hears voice" and the meaning of "see" in "I see colours". — Michael

This sense of acquaintance with mental phenomena occurs also in veridical perception, and this is all that is meant when the indirect realist says that awareness of distal objects is mediated by awareness of mental phenomena. — Michael

• How do we perceive the external world?
• What is the relationship between our perceptions and the external objects themselves?
• Are our perceptual experiences direct or mediated?

2.The act of processing visual data: To perceive --> causes
3. Having the resulting conscious experience: To see. — AmadeusD

Sense data just is the unmediated empirical affect the object has, that data, that affect, conditioned by something very different, is the subsequent mediated representation of the perceived object. — Mww

To mediate is to arbitrate or condition; that which is a perception cannot arbitrate or be arbitrated by, another perception. Perception mediated by perception is improper and confusing;
Sense data just is the unmediated empirical affect the object has, that data, that affect, conditioned by something very different, is the subsequent mediated representation of the perceived object. This is indirect realism. — Mww

(2) that our visual perception of […] material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part) — Michael

Then where is the mediation of our perception of visual objects by the perception of some other entities such as sense-data?
— Luke

We feel pain – a mental phenomenon – and it is in feeling this pain that we feel the fire. We taste a sweet taste – a mental phenomenon – and it is in tasting this sweet taste that we taste the sugar. We see shapes and colours – mental phenomena – and it is in seeing these shapes and colours that we see the cow. — Michael

You misinterpret what "perceive mental phenomena" means. I feel pain, and pain is a mental phenomenon. The schizophrenic hears voices, and these voices are a mental phenomenon. I see colours, and colours are a mental phenomenon. This is all that is meant. — Michael

And this is where you're reading something into the grammar that just isn't there. — Michael

The existence of something like a mental representation is what it means for our perception of distal objects to be mediated. — Michael

I addressed this before when I asked you to explain the difference between "seeing" a mental representation and "having" a mental representation. You were unable to do so. And that is precisely because there is no difference. — Michael

Naïve realism is a theory in the philosophy of perception: primarily, the philosophy of vision. Historically, the term was used to name a variant of “direct realism,” which claimed (1) that everyday material objects, such as caterpillars and cadillacs, have mind-independent existence (the “realism” part); (2) that our visual perception of these material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part); and (3) these objects possess all the features that we perceive them to have (the “naïve” part). In this, the theory contrasted with theories such as scientific direct realism (which rejected (3)), indirect realism (which rejected (2) and (3)), and phenomenalism, which rejected (1). Today, however, most philosophical theories of visual perception would endorse at least claims (1) and (2), and many would also endorse (3). In this setting, “naïve realism” has taken on a more precise use. As understood today, the naïve realist claims that, when we successfully see a tomato, that tomato is literally a constituent of that experience, such that an experience of that fundamental kind could not have occurred in the absence of that object. As naïve realism, thus understood, sees perception as fundamentally involving a relation between subjects and their environments, the position is also sometimes known as “relationalism” in the contemporary literature. Typically, today’s naïve realist will also claim that the conscious “phenomenal” character of that experience is shaped by the objects of perception and their features, where this is understood in a constitutive, rather than merely a causal, sense. On such a view, the redness that I am aware of when I look at a ripe tomato is a matter of my experience acquainting me with the tomato’s color: the redness that I am aware of in this experience just is the redness of the tomato. As such a view appears to commit its proponent to a version of claim (3) above—that for one to see an object to have a feature, the object must actually have that feature—the inheritance of the name “naïve” realism seems appropriate. As for whether there can be naïve realist theories of senses other than vision, this is an issue that awaits a more detailed exploration.

The key parts are in bold.

Specifically, I think that "our visual perception of these material objects is not mediated by the perception of some other entities, such as sense-data" means "the conscious 'phenomenal' character of that experience is shaped by the objects of perception and their features, where this is understood in a constitutive, rather than merely a causal, sense." — Michael

...our visual perception of [...] material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part)

...the conscious “phenomenal” character of that experience is shaped by the objects of perception and their features, where this is understood in a constitutive, rather than merely a causal, sense. — Michael

Naïve realism is a theory in the philosophy of perception: primarily, the philosophy of vision. Historically, the term was used to name a variant of “direct realism,” which claimed (1) that everyday material objects, such as caterpillars and cadillacs, have mind-independent existence (the “realism” part); (2) that our visual perception of these material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part); and (3) these objects possess all the features that we perceive them to have (the “naïve” part). In this, the theory contrasted with theories such as scientific direct realism (which rejected (3)), indirect realism (which rejected (2) and (3)), and phenomenalism, which rejected (1). Today, however, most philosophical theories of visual perception would endorse at least claims (1) and (2), and many would also endorse (3). In this setting, “naïve realism” has taken on a more precise use.

To clarify, when you say that, according to naive realism, perceptions and perceived distal objects have the same physical constituents, do you take this to mean that perceptions and the perceived distal objects are identical?
— Luke

You'll have to ask naive realists for specifics of what they mean — Michael

This is the very point I am making. Non-naive direct realism is indirect realism given that they both accept that distal objects and their properties are not constituents of experience — Michael

I can only quote what they say — Michael

which is that the relation between conscious experience and distal objects is more than just causal and is non-representational, using the term "constituent", which means "being a part". — Michael

Indirect realists don't argue that percepts exist, that distal objects and their properties are not constituents of these percepts, and that perception is indirect, as if this latter claim is distinct from the other two. Rather, by "perception is indirect" they just mean that percepts exist and that distal objects and their properties are not constituents of these percepts – and the science of perception supports this. — Michael

What is the physical/physiological difference between mental representations mediating perceptions of real objects and not mediating perceptions of real objects? — Michael